Furnace short cycling
Hi everyone, First time posting but long time reader of these forums. Down to the brass tax here, I have a suburban sf 25 that cycles on the limit switch. I have not bench tested unit yet or checke...
Forum Discussion
Update,
Pulled furnace again and bench tested with the shell on. Furnace short cycles every 3 to 4 min. Now the strange part is if I pull the housing off the furnace it ran for 20min without short cycling once. Not sure where to go with this one now. Could it be the blower motor is not pushing enough rpms to move air fast enough to cool housing? Did I end up with a limit switch that has too low of trip temperature? All the blades are clean, fully charged battery and a WC of 11. More ducts does not seem to be my issue. With temp probe on the burner chamber by the limit switch it trips at around 167. Fan blades are all clean of any debris/dust.
Cheers.
Cheers
Pulled furnace again and bench tested with the shell on. Furnace short cycles every 3 to 4 min. Now the strange part is if I pull the housing off the furnace it ran for 20min without short cycling once. Not sure where to go with this one now. Could it be the blower motor is not pushing enough rpms to move air fast enough to cool housing? Did I end up with a limit switch that has too low of trip temperature? All the blades are clean, fully charged battery and a WC of 11. More ducts does not seem to be my issue. With temp probe on the burner chamber by the limit switch it trips at around 167. Fan blades are all clean of any debris/dust.
Cheers.
Cheers
